Cancer begins when a cell begins dividing uncontrollably. Eventually, these cells form a visible mass or tumor. Solid tumors are masses of abnormal tissue that originate in organs or soft tissues that typically do not include fluid areas. Some examples of solid tumors include: pancreatic cancer, lung cancer, brain cancer, liver cancer, uterine cancer, and colon cancer.
Traditionally, tumors have been treated with surgical resection, radiation, and/or chemotherapy. Surgical resection involves the removal of tumor tissue. Radiation uses beams of intense energy to kill cancer cells and to shrink tumors. And chemotherapy involves the use of therapeutic agents or drugs to treat cancer. But surgical resection may not completely remove a tumor. Radiation and chemotherapy can have undesirable systemic side effects, including extreme fatigue, hair loss, infection, nausea and vomiting, and others that limit their usefulness. More recently, direct activation of the patient's immune system to attack cancerous cells has shown promise in treating certain solid tumors, but not all. Thus, the need for an improvement in both the safety and the efficacy of current therapy still exists.
Use of localized intra-arterial therapies, including trans-arterial chemo-delivery (TAC) or trans-arterial chemo-embolization (TACE), has been shown to be clinically beneficial for a certain subset of solid tumors. TAC or TACE can involve imaging an organ having a tumor using angiography, isolating a branch of the artery that feeds the tumor or portion of the organ containing the tumor, and then locally injecting chemotherapy in a bolus fashion via the isolated artery. Localized intra-arterial therapies allow higher drug concentration to reach the tumor, overcoming the problem of poor blood flow to tumor mass in comparison to healthy tissue. Furthermore, localized intra-arterial therapies can also take advantage of the first pass effect of chemotherapeutics by generating higher level drug concentrations at the tumor cell membrane and therefore enhancing cellular drug uptake as compared to non-localized infusion. Lastly, local delivery can reduce systemic side effects of chemotherapy.
One of the limitations of TAC and TACE is the need for selective cannulation and isolation of the tumor feeder vessel or arterial branch that can target the smallest portion of the organ containing the tumor. But it may be difficult to target and limit drug delivery to a small portion of the organ containing the tumor while achieving desired efficacy levels with the cancer treatment. On the one hand, limiting drug delivery to a small portion of the organ can reduce the potential impact of the administered drug on surrounding healthy tissue. But on the other hand, when the isolated region becomes too small, drug uptake levels by the tumor may decrease and reduce the efficacy of the cancer treatment. Given these limitations, a method to deliver a sufficient dose of a chemotherapeutic drug in addition to and independent of the need to cannulate and isolate to a specific feeding/supplying branch of a tumor feeder vessel is highly desirable.
Pancreatic Cancer
In 2016, pancreatic cancer ranked as the fourth leading cause of cancer death in the United States, and the tenth most commonly diagnosed tumor type in men and women. Estimates of incidence and deaths caused by pancreatic cancer are approximately 53,070 and 41,780, respectively (American Cancer Society: Cancer Facts and Figures, American Cancer Society, 2016). Projections based on the changing demographics of the United States population and changes in incidence and death rates reveal that, unless earlier diagnosis is made possible or better treatment options become available, pancreatic cancer is anticipated to move from the fourth to the second leading cause of cancer death in the United States by 2020.
Systemic chemotherapy as treatment for pancreatic cancer may be modestly effective due to low drug penetration in the pancreas because a drug infused systemically only moderately penetrates the pancreas, which may generally increase toxicity within a patient's body but not have an effect on the cancer. In many instances, tumors located in the pancreas are located in tissue surrounding an artery but not in a region of an artery that can be targeted and isolated. Accordingly, it may be difficult for a biologic agent or drug to reach and treat the tumors. Among solid tumors, drug delivery to pancreatic tumors is especially difficult due to the hypo-vascular and poorly perfused nature of the pancreas. The unique environment of the pancreas lends itself to reduced drug levels within the organ tissue, which reduces the effectiveness of systemic chemotherapy that relies on a functional vasculature for delivery to tumor cells. Also, the effect of chemotherapy is concentration dependent, and systemic infusion oftentimes results in low concentrations. Aside from dosing limitations in treating pancreatic cancer, many systemic side effects of chemotherapeutic agents can result from the treatment.
In an attempt to increase the effectiveness of chemotherapeutic agents on pancreatic tumors while decreasing systemic toxicity, various researchers have delivered drugs directly to the pancreas using traditional endovascular catheters. These initial attempts have been limited due to the redundant nature of blood supply to the pancreas and its adjacent organs. Non-selective engagement of the pancreatic vessels can also lead to the wash through of chemotherapy to other adjacent organs. Most of the arterial branches to the pancreas are small; thus, selective engagement of these small branches via conventional catheters is difficult. Thus, there is a need to address these and other deficiencies.
Lung Cancer
Lung cancer is another deadly cancer that is difficult to treat. Lung cancer is responsible for 23% of total cancer deaths. Long-term exposure to tobacco smoke causes 80 to 90% of lung cancers. Nonsmokers account for 10 to 15% of lung cancer cases, and these cases are often attributed to a combination of genetic factors or other environmental exposures (Vogl, T. J., et al., Seminars in Interventional Radiology, 2013, 30(2): 176-184).
Common treatments for lung cancer depend on the cancer's specific pathology, staging, and the patient's performance status (e.g., ability to breath). Traditional treatment options are surgery, chemotherapy, immunotherapy, radiation therapy, and palliative care. Intravascular techniques for localized delivery of chemotherapeutic agents have also been used to treat lung cancer, and include cancer therapy such as arterial chemoembolization, bronchial artery infusion (BAI), isolated lung perfusion (ILP), and lung suffusion. Chemotherapeutics approved for the treatment of non-small cell lung cancer in the United States include methotrexate, paclitaxel albumin-stabilized nanoparticle formulation, afatinib dimaleate, everolimus, alectinib, pemetrexed di sodium, atezolizumab, bevacizumab, carboplatin, ceritinib, crizotinib, ramucirumab, docetaxel, erlotinib hydrochloride, gefitinib, afatinib dimaleate, gemcitabine hydrochloride, pembrolizumab, mechlorethamine hydrochloride, methotrexate, vinorelbine tartrate, necitumumab, nivolumab, paclitaxel, ramucirumab, and osimertinib, and the combinations carboplatin-taxol and gemcitabine-ci splatin (https://www.cancer.gov/aboutcancer). Drugs approved for the treatment of small cell lung cancer include methotrexate, everolimus, doxorubicin hydrochloride, etoposide phosphate, topotecan hydrochloride, mechlorethamine hydrochloride, and topotecan (https://www.cancer.gov/aboutcancer). Lung cancer such as small cell lung cancer can sometimes be treated with a combination of radiation therapy and one or more chemotherapeutics. But other types of lung cancer such as non-small cell lung cancer may not be sensitive to current chemotherapeutics. In many instances, current treatment methods are not effective at providing meaningful treatment or palliative care. Thus, it is desirable to have a more effective method for treating lung cancer tumors.
Brain Cancer
Malignant gliomas comprise up to 80% of primary malignant brain tumors in the adults. Among these, glioblastomas are the most deadly and account for 82% of all malignant gliomas (Suryadevra, C. M., et al., Surg. Neurol. Int., 2015, 6(1):S68-S77). The current standard of care includes surgical resection, followed by adjuvant external beam radiation and chemotherapy with drugs such as temozolomide. Conventional therapy is nonspecific and often results in a tragic destruction of healthy brain tissue. These treatments can be incapacitating and produce a median overall survival of just twelve to fifteen months. In addition, the invasive properties of glioblastomas make complete resection difficult and the glioblastomas may recur following initial treatment. Malignant gliomas are also highly vascularized tumors, and their unique capacities for regulating angiogenesis contribute to their resistance against known therapies.
Malignant gliomas, including glioblastoma multiforme, have been treated with inter-arterial chemotherapy. Typically, a catheter is inserted in the femoral artery and ends in the carotid artery, while a separate microcatheter is also inserted into the femoral artery and used to explore the specific vessels feeding the tumor for administration of the chemotherapy (Burkhardt, J-K., et al., Interventional Radiology, 2011, 17:286-295). But such methods are not always effective and can be improved.
Liver Cancer
Liver cancer is another difficult-to-treat cancer characterized by solid tumors. In 2016, an estimated 39,230 adults (28,410 men and 10,820 women) in the United States will be diagnosed with primary liver cancer. Liver cancer also commonly metastasizes to other parts of the body. It is estimated that 27,170 deaths (18,280 men and 8,890 women) from this disease will occur this year. Liver cancer is the tenth most common cancer and the fifth most common cause of cancer death among men. It is also the eighth most common cause of cancer death among women (American Cancer Society: Cancer Facts and Figures, American Cancer Society, 2016). When compared with the United States, liver cancer is much more common in developing countries within Africa and East Asia. In some countries, it is the most common cancer type. The one-year survival rate for people with liver cancer is 44%. The five-year survival rate is 17%. For the 43% of people who are diagnosed at an early stage, the five-year survival rate is 31%, while it is only 11% if the cancer has spread to surrounding tissues or organs and/or the regional lymph nodes. If the cancer has spread to a distant part of the body, the 5-year survival rate is only 3% (http://www.cancer.net/cancer-types/liver-cancer/statistics).
Currently, patients with hepatocellular carcinoma and cirrhosis are frequently treated with non-specific trans-arterial therapy using techniques that deliver treatments directly into the liver (Lewandowski, R. J., et al., Radiology, 2011, 259(3):641-657). Physicians use the fermoral artery to gain access to the hepatic artery, one of two blood vessels that feed the liver. Trans-arterial therapy such as TACE involves delivery of chemotherapy directly to the liver, followed by a process to embolize the chemotherapy. In this therapy, a thick, oily substance (for example, Lipiodol) is mixed with chemotherapy (for example, floxuridine, sorafenib tosylate or a mixture of platinol, mitomycin, and adriamycin) and injected under radiological guidance directly into the artery supplying the tumor via a catheter. The Lipiodol, or other particles, helps to contain the chemotherapy within the tumor and blocks further blood flow, thus cutting off the tumor's food and oxygen supply. TACE with doxorubicin-filled beads delivers the beads directly to the liver, which releases chemotherapy slowly over time and also blocks the blood flow to the tumor. In a similar therapy, radioactive yttrium beads are delivered via a catheter into the hepatic artery. The beads deliver radiation to the tumor, which kills the tumor cells, although other unintended areas of the liver may also receive radiation, creating undesirable destruction of healthy tissue. Thus, there is a need to improve current treatment methods.
Uterine Cancer
In 2016, an estimated 60,050 women in the United States were diagnosed with uterine endometrial cancer, with an estimated 10,470 deaths occurring (http://www.cancer.net/cancer-types/uterine-cancer/statistics). Uterine cancer is the fourth most common cancer for women in the United States. The incidence of endometrial cancer is rising, mainly due to a rise in obesity, which is an important risk factor for this disease. It is the sixth most common cause of cancer death among women in the United States with the 5-year survival rate being 82%.
Concurrent chemoradiotherapy (CCRT) is the main treatment for locally advanced cervical cancer. Neoadjuvant chemotherapy (NAC) was widely employed until CCRT became the standard, and conflicting results have been reported. Neoadjuvant intra-arterial chemotherapy (IANAC) is another method for delivering NAC as an alternative to systemic chemotherapy. IANAC has been reported to achieve beneficial results that cannot be obtained by systemic chemotherapy or CCRT. Kawaguchi et al. have reported that IANAC with cisplatin followed by radical hysterectomy or radiotherapy afforded similar results to concurrent chemoradiotherapy for stage IIIB cervical cancer (Kawaguchi et al., World Journal of Oncology, 2013, 4(6):221-229). Drugs approved for use in the United States for the treatment of cervical cancer include bevacizumab, bleomycin, and topotecan hydrochloride, and the combination gemcitabine-cisplatin. Uterine cancer of endometrial origin may be treated with, for example, megestrol acetate. But many systemic side effects of chemotherapeutic agents can result from current treatment methods. It is desirable to have a specific means of targeting uterine tumors.
Colon Cancer
In the United States, colorectal cancer is the fourth most common cancer diagnosed each year for all adults combined. Separately, it is the third most common cancer in men and third most common cancer in women. In 2016, an estimated 134,490 adults in the United States were diagnosed with colorectal cancer, with 95,270 new cases of colon cancer and 39,220 new cases of rectal cancer. It is estimated that 49,190 deaths (26,020 men and 23,170 women) were attributed to colon or rectal cancer in 2016. Colorectal cancer is the second leading cause of cancer death in the United States, although when it is detected early, it can often be cured. The death rate from this type of cancer has been declining since the mid-1980s, probably because of an improvement in early diagnosis. The 5-year survival rate colorectal cancer is 65%, while the 10-year survival rate is 58% (http://www.cancer.net/node/18707).
When possible, surgical removal of colorectal tumors is the treatment of choice as it can eliminate the cancer completely. However, metastasis to other organs, particularly the liver and the lung, is common and complicates the treatment of colon and rectal cancer dramatically. It is therefore desirable to have a method of treating metastasized colon and rectal cancers that are present in other organs of the body. Drugs approved for use in treating colon cancer in the United States include bevacizumab, irinotecan hydrochloride, capecitabine, cetuximab, ramucirumab, oxaliplatin, 5-FU, fluorouracil, leucovorin calcium, trifluridine, tipiracil hydrochloride, oxaliplatin, panitumumab, ramucirumab, regorafenib, ziv-aflibercept and the combinations capox, folfiri-bevacizumab, folfiri-cetuximab, FU-LV, xeliri and xelox.